View source for 1wbp


==SRPK1 bound to 9mer docking motif peptide==
<StructureSection load='1wbp' size='340' side='right'caption='[[1wbp]], [[Resolution|resolution]] 2.40&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1wbp]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1WBP OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1WBP FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 2.4&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=ACT:ACETATE+ION'>ACT</scene>, <scene name='pdbligand=ADP:ADENOSINE-5-DIPHOSPHATE'>ADP</scene></td></tr>
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=1wbp FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1wbp OCA], [https://pdbe.org/1wbp PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1wbp RCSB], [https://www.ebi.ac.uk/pdbsum/1wbp PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1wbp ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/SRPK1_HUMAN SRPK1_HUMAN] Serine/arginine-rich protein-specific kinase which specifically phosphorylates its substrates at serine residues located in regions rich in arginine/serine dipeptides, known as RS domains and is involved in the phosphorylation of SR splicing factors and the regulation of splicing. Plays a central role in the regulatory network for splicing, controlling the intranuclear distribution of splicing factors in interphase cells and the reorganization of nuclear speckles during mitosis. Can influence additional steps of mRNA maturation, as well as other cellular activities, such as chromatin reorganization in somatic and sperm cells and cell cycle progression. Isoform 2 phosphorylates SFRS2, ZRSR2, LBR and PRM1. Isoform 2 phosphorylates SRSF1 using a directional (C-terminal to N-terminal) and a dual-track mechanism incorporating both processive phosphorylation (in which the kinase stays attached to the substrate after each round of phosphorylation) and distributive phosphorylation steps (in which the kinase and substrate dissociate after each phosphorylation event). The RS domain of SRSF1 binds first to a docking groove in the large lobe of the kinase domain of SRPK1. This induces certain structural changes in SRPK1 and/or RRM2 domain of SRSF1, allowing RRM2 to bind the kinase and initiate phosphorylation. The cycles continue for several phosphorylation steps in a processive manner (steps 1-8) until the last few phosphorylation steps (approximately steps 9-12). During that time, a mechanical stress induces the unfolding of the beta-4 motif in RRM2, which then docks at the docking groove of SRPK1. This also signals RRM2 to begin to dissociate, which facilitates SRSF1 dissociation after phosphorylation is completed. Isoform 2 can mediate hepatitis B virus (HBV) core protein phosphorylation. It plays a negative role in the regulation of HBV replication through a mechanism not involving the phosphorylation of the core protein but by reducing the packaging efficiency of the pregenomic RNA (pgRNA) without affecting the formation of the viral core particles. Isoform 1 and isoform 2 can induce splicing of exon 10 in MAPT/TAU. The ratio of isoform 1/isoform 2 plays a decisive role in determining cell fate in K-562 leukaemic cell line: isoform 2 favors proliferation where as isoform 1 favors differentiation.<ref>PMID:8208298</ref> <ref>PMID:11509566</ref> <ref>PMID:12134018</ref> <ref>PMID:15034300</ref> <ref>PMID:9237760</ref> <ref>PMID:10049757</ref> <ref>PMID:10390541</ref> <ref>PMID:14555757</ref> <ref>PMID:16122776</ref> <ref>PMID:18155240</ref> <ref>PMID:18687337</ref> <ref>PMID:19886675</ref> <ref>PMID:19240134</ref> <ref>PMID:19477182</ref> <ref>PMID:20708644</ref> <ref>PMID:16209947</ref> 
== Evolutionary Conservation ==
[[Image:Consurf_key_small.gif|200px|right]]
Check<jmol>
  <jmolCheckbox>
    <scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/wb/1wbp_consurf.spt"</scriptWhenChecked>
    <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked>
    <text>to colour the structure by Evolutionary Conservation</text>
  </jmolCheckbox>
</jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/main_output.php?pdb_ID=1wbp ConSurf].
<div style="clear:both"></div>
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
The arginine-serine (RS)-rich domain of the SR protein ASF/SF2 is phosphorylated by SR protein kinases (SRPKs) and Clk/Sty kinases. However, the mode of phosphorylation by these kinases and their coordination in the biological regulation of ASF/SF2 is unknown. Here, we report the crystal structure of an active fragment of human SRPK1 bound to a peptide derived from an SR protein. This structure led us to identify a docking motif in ASF/SF2. We find that this docking motif restricts phosphorylation of ASF/SF2 by SRPK1 to the N-terminal part of the RS domain - a property essential for its assembly into nuclear speckles. We further show that Clk/Sty causes release of ASF/SF2 from speckles by phosphorylating the C-terminal part of its RS domain. These results suggest that the docking motif of ASF/SF2 is a key regulatory element for sequential phosphorylation by SRPK1 and Clk/Sty and, thus, is essential for its subcellular localization.

Interplay between SRPK and Clk/Sty kinases in phosphorylation of the splicing factor ASF/SF2 is regulated by a docking motif in ASF/SF2.,Ngo JC, Chakrabarti S, Ding JH, Velazquez-Dones A, Nolen B, Aubol BE, Adams JA, Fu XD, Ghosh G Mol Cell. 2005 Oct 7;20(1):77-89. PMID:16209947<ref>PMID:16209947</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 1wbp" style="background-color:#fffaf0;"></div>

==See Also==
*[[Serine/threonine protein kinase 3D structures|Serine/threonine protein kinase 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Homo sapiens]]
[[Category: Large Structures]]
[[Category: Adams JA]]
[[Category: Aubol BE]]
[[Category: Chakrabarti S]]
[[Category: Fu X-D]]
[[Category: Ghosh G]]
[[Category: Gullinsgrud J]]
[[Category: McCammon JA]]
[[Category: Ngo JC]]
[[Category: Nolen B]]